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Malm Gulch Petrified Forest - Idaho BLM Area of Interest

More than fifty million years ago, giant sequoia forests covered these rugged, hilly highlands and blanketed the forest floor of Malm Gulch. Today, a petrified forest stands as evidence of the volcanic explosions that took place here about 51 million years ago and continued until about 40 million years ago. Flows and tuffs cover approximately 1,900 square miles of east-central and south-central Idaho and are up to 10,000 feet thick. Twin Peaks caldera, west of Challis, is roughly 12½ miles in diameter and is the major source for the volcanic ash in Malm Gulch. Lavender, light green and white hillsides formed after the volcanic ash cooled and solidified. Remnants of this giant sequoia forest can still be found by walking around this area. Fences built in the 1970s protect the last remnants of this fragile and unique petrified forest. Read On

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